NEW YORK — Vice President Joe Biden on Thursday compared his rival's policies to a gun pointed at Americans, and the GOP nominee's son said he's tempted to "take a swing" at President Barack Obama as emotions run high in the closely fought White House race.

The barbs are being delivered with a smile, but their sharpness is a reflection of just how tight the race is 19 days out. Democrats are pushing the accusation that Mitt Romney is being dishonest, with Obama's refrain since Tuesday's debate that the GOP nominee is offering "a sketchy deal."

"I don't think they were just sketchy," Biden said at a rally in Las Vegas. "I think they were Etch-a-Sketchy."

Senate Majority Leader Harry Reid warmed up the crowd in Nevada by saying Romney is "giving used car salesmen a bad name." Reid then introduced Biden as a man "who has shown us his tax returns" — a contrast to Romney's refusal to release more than the past two years. His red-meat offering whipped the partisan crowd into whoops and applause as Biden took the stage.

Vice President Joe Biden speaks during a campaign rally at the Culinary Academy Events Center, Thursday, Oct. 18, 2012, in Las Vegas. Biden, on Thursday, derided the campaigns of Republican challenger Mitt Romney and vice presidential candidate Paul Ryan as being built on negative views of "makers" and "takers" in America, with half the population dependent on the other for support. (Julie Jacobson, Associated Press)

"Ryan has written a book called the 'Young Guns' with two other members of the House," Biden said. "Unfortunately, the bullets are aimed at you."

Romney campaign spokesman Brendan Buck responded that Biden's "over-the-top rhetoric" was disappointing but not surprising. "In the absence of a vision or plan to move the country forward, the vice president is left only with ugly political attacks beneath the dignity of the office he occupies," Buck said in a statement emailed to reporters.

Ryan, speaking at a campaign stop in Ocala, Fla., before Biden delivered his comments, accused Obama of sending a divisive message.

"He's basically trying to disqualify his opponent with a sea of negativity," Ryan said. "He's trying to divide this country, pitting people against each other. He's trying to win this election by default. You know what? We're not going to let him get away with that."

The finger-pointing and recrimination comes after a heated debate this week between Obama and Romney. The GOP nominee's oldest son, Tagg, was asked by a North Carolina radio host Wednesday how it to hear the president "call your dad a liar" — a word Obama never used although he repeatedly said Romney's statements weren't true.

Tagg Romney laughed at the question. "You want to rush down the debate stage and take a swing at him. But you know you can't do that because, well first cause there is a lot of Secret Service between you and him, but also because it's the nature of the process," he said.

Another Romney son, Josh, said in an appearance on ABC's "The View" on Thursday that his brother didn't mean it but was responding to the emotions that arise in the heat of the campaign.

"That brother has slugged me a couple times. I assure you President Obama has nothing to worry about," Josh Romney quipped. "You really don't like to see your dad get beat up by the media or President Obama or whatever it is, so you take it pretty personally. But I think that was just something he was saying off the cuff and I assure you he didn't mean it."

Their mother, Ann Romney, also appearing on "The View," said the negativity of the campaign is very difficult for their family and she initially didn't want to go through another campaign after losing the 2008 Republican primary. She said she agreed to a second run because she feels her husband is uniquely qualified to bring economic hope and prosperity to America

But she didn't hesitate when co-host Barbara Walters asked whether her husband's political career will end if he doesn't win on Nov. 6.

"Absolutely," Mrs. Romney said. "He will not run again, nor will I."

The bickering between campaigns was supposed to take a break Thursday night as both candidates address the Alfred E. Smith Memorial Foundation Dinner, a white-tie gala at New York City's Waldorf Astoria Hotel that has been a required stop for politicians since the end of World War II. Obama also played for laughs on Comedy Central's "The Daily Show" while he's in Manhattan for an episode that would air late Thursday.

The president campaigned earlier Thursday in tightly contested New Hampshire and asked the state's voters to give him more time in office to get the economy back on track. "I need your help to finish what we started in 2008."

The Romney campaign was shifting resources and some workers out of North Carolina, a campaign official saying he was more confident of a victory there. The state's 24 Republican campaign offices — Obama has 54 — will remain open and the get-out-the-vote efforts will continue, campaign official Michael Levoff said.

The evening's political dinner is named for the four-term Democratic governor of New York who lost the 1928 presidential race to Republican Herbert Hoover. Smith was the first Catholic to run for president and the dinner named for him is organized by the Catholic Archdiocese of New York for the benefit of needy children.

In keeping with tradition, both candidates have prepared lighthearted fare for the event. That was the case almost precisely four years ago when Obama and GOP nominee John McCain poked fun at themselves and each other just a day after an intense presidential debate at Hofstra University on Long Island.

As in 2008, this year's dinner follows a confrontational debate, also at Hofstra, lending an air of drama to the pivot from acrimony to humor. Obama campaign spokeswoman Jen Psaki mocked the high expectations that both campaigns set for their rivals before the debates.

"I will say Mitt Romney has practiced for longer than any presidential candidate in history for tonight," Psaki told reporters traveling with Obama. "And we expect him to be drop-on-the-floor funny. And the president will make his way through."

What's more, the dinner's host is Cardinal Timothy M. Dolan, president of the U.S. Conference of Catholic Bishops, which has clashed with the Obama administration over contraception provisions in the new health care law. Dolan has said he received "stacks of mail" protesting the dinner invitation to Obama. But Dolan has sought to avoid playing political favorites, even delivering benedictions at both the Republican and Democratic national conventions this summer.

On the celebrity front, Obama picked up the endorsement of rock star Bruce Springsteen, who also backed the Democrat in 2008 and Thursday campaigned for Obama in Ohio with former President Bill Clinton.

"For 30 years I've been writing about the distance between the American dream and American reality," Springsteen said, reading from a statement on his music stand. "Our vote is the one principal way we get to determine that distance."

Associated Press writers Nedra Pickler and Ken Thomas in Washington and Tamara Lush in Ocala, Fla., contributed to this report.